Dynamics of stochastically excited energy harvesting systems with impact

Focusing on rigid impact (RI) and elastic impact (EI) vibratory energy harvesting systems with the excitation of Gaussian white noise, the stochastic response characteristics, and energy harvesting performance of the systems are presented and compared. The stochastic averaging of the energy envelope is introduced with different processing methods in these systems to derive the theoretical probability density functions. Numerical simulation results verify the effectiveness of such theoretical methods. Effects of the coefficients and positions of impact barriers in the systems on the mean square voltage are analyzed. The analysis can help explain the physical mechanisms of the systems and provide ideas for optimizing energy harvesting performance by properly tuning the coefficients. Effects of the existence of three kinds of impact on the output energy are explored and compared. It is found that the existence of EI can help to enhance the energy harvesting performance of the system in most cases, and setting the impact barrier at the origin is more conducive to harvesting energy compared with other impact positions.